RFI and EMI - Contacts, Fingerstock and Gaskets

Part Number	Description / PDF	Quantity
3020301 Würth Elektronik Midcom	GASKET FABRIC/FOAM 3MMX1M RECT	284
SG252280C-48 Leader Tech Inc.	FSG, .252"H X .280"W X 48"L	3289
67SLG100100100PI00 Laird - Performance Materials	METAL FILM OVER FOAM CONTACTS	55
30207032 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	97
0097053702 Laird - Performance Materials	GASKET BECU 28.7X304.8MM	408
2108613-5 TE Connectivity AMP Connectors	2.4H SPRING FINGER W/EMBOSS	0
5409-0006-20-300 Leader Tech Inc.	M83528/009B006, AG/AL FILLED SIL	3
0097060602 Laird - Performance Materials	FINGERSTOCK BECU 9.65X406.4MM	0
19-04-16162-S6305 Parker Chomerics	CHO-SEAL S6305 NI/C 0.100" 1'	0
3851040 Würth Elektronik Midcom	WE-CSGS CONTACT SPRING GASKET	49
WS-4505-01-A 3G Shielding Specialties	CONDUCTIVE PE FOAM EMI GASKET	11
3031004 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	0
WS-3350-KC-2400 3G Shielding Specialties	FAB/FOAM GASKET .500WX.400HX24L	100
3020505 Würth Elektronik Midcom	GASKET FABRIC/FOAM 5MMX1M SQ	162
0097063702 Laird - Performance Materials	GASKET BECU 13X406.4MM	0
3029040030030 Würth Elektronik Midcom	WE-SMGS SURFACE MOUNT SOLDERABLE	2204
S7231-45R Harwin	RFI SHIELD FINGER AU 1.28MM SMD	10660
3031008 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	5
30205015 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	36
302095095 Würth Elektronik Midcom	WE-LT CONDUCTIVE SHIELDING GASKE	0

RFI and EMI - Contacts, Fingerstock and Gaskets

1. Overview

RF/IF (Radio Frequency/Intermediate Frequency) and RFID (Radio Frequency Identification) systems require effective electromagnetic interference (EMI) and radio frequency interference (RFI) shielding to maintain signal integrity. Contacts, fingerstock, and gaskets are critical components for ensuring electrical continuity and shielding performance in electronic enclosures. These components prevent electromagnetic leakage while maintaining mechanical functionality in connectors, housings, and assemblies.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Contacts	Conductive elements for maintaining electrical connections under compression	RF connectors, PCB grounding pads
Fingerstock	Resilient metal strips with finger-like projections for continuous shielding	Server chassis, military equipment
Gaskets	Conductive elastomers or mesh materials for sealing gaps	Automotive sensors, medical devices

3. Structure and Composition

Typical structures include:

Contacts: Beryllium copper or phosphor bronze cores with conductive platings (gold, silver, nickel)
Fingerstock: Canted coil springs or stamped metal fingers with corrosion-resistant coatings
Gaskets: Silicone rubber with embedded silver-aluminum particles or wire mesh

4. Key Technical Parameters

Parameter	Typical Range	Significance
Contact Resistance	0.1-10 m	Affects signal transmission efficiency
Shielding Effectiveness	60-120 dB (100 MHz-10 GHz)	Determines EMI/RFI attenuation
Compression Force	0.5-5 N/mm	Impacts mechanical durability
Temperature Range	-55 C to +150 C	Defines operational stability

5. Application Fields

Main industries include:

Telecommunications (5G base stations, microwave links)
Automotive (V2X communication systems, radar sensors)
Aerospace (avionics shielding compartments)
Medical (MRI shielding enclosures)

6. Leading Manufacturers and Products

Manufacturer	Representative Products
Parker Chomerics	CHO-SEAL conductive gaskets
Laird Performance Materials	Form-in-Place EMI gaskets
3M	EMI Shielding Tapes 9703/9706
Samtec	RFI/EMI shielded connectors

7. Selection Recommendations

Considerations include:

Frequency range of the application (higher frequencies require tighter tolerances)
Environmental conditions (temperature, humidity, chemical exposure)
Material compatibility (avoid galvanic corrosion between mating surfaces)
Cost-effectiveness (balance performance vs. budget constraints)

Case Study: In automotive radar systems, Parker Chomerics' silicone-based gaskets reduced EMI leakage by 40% compared to traditional metal fingerstock.

8. Industry Trends

Key development directions:

Miniaturization for 5G mmWave applications
Low-PIM (Passive Intermodulation) material formulations
Multi-functional integration with thermal management
RoHS-compliant plating processes (eliminating hexavalent chromium)